1. Field of the Invention
Example embodiments of the present invention relate to a method for preventing reader collision, a method for driving an RFID reader using the method for preventing reader collision, and an RFID reader for performing the method for preventing reader collision. More particularly, example embodiments of the present invention relate to a method for preventing collision among a plurality of readers, a method for driving an RFID reader using the method for preventing reader collision, and an RFID reader for performing the method for preventing reader collision.
2. Description of the Related Art
In general, a radio frequency identification (RFID) system includes a plurality of RFID tags, a plurality of RFID readers and an application software part. The RFID tag is attached to a surface of a product and contains information of the product. The RFID reader communicates with the RFID tag through a wireless signal to receive the information of the product. The application software part receives the information of the product from the RFID reader to perform various applications.
In the RFID system, an RFID collision may happen, so that a function of the RFID system may be deteriorated. The RFID collision means a state that the readers cannot read signals generated from a plurality of tags or a plurality of readers, since the tags or the readers occupy same time or same frequency band so that the signals generated from the tags or the readers are mixed with each other.
In general, the RFID collision may be classified as either a tag collision or a reader collision. The tag collision is a collision between tags when one reader reads signals of the tags, and the reader collision is a collision between readers. The reader collision may be classified as either a multiple-readers-to-tag interference or a reader-to-reader interference.
The multiple-readers-to-tag interference happens when a plurality of readers try to access to one tag simultaneously. The reader-to-reader interference happens when a signal generated by a target reader arrives at an adjacent reader to be mixed with a signal from a tag.